The railroad companies of the United States are, and have been for a number of years, engaged in piggyback operations, i.e. in the hauling of truck trailers on railroad cars.
Within the whole area of these operations the Piggyback Industry has had a continuous and increasingly costly problem with the theft of tires from the trailers. The majority of such thefts are characterized by what is known as "quick change-outs" and this involves swapping the entire wheel and tire, including the rim, for a similar rim and a poorer tire, often one which is virtually worn out.
Naturally, as such practices are costly to the Piggyback Industry, many attempts have been made to control and prevent this type of theft. So called Tattlecaps, as for example a device to provide an indication that the rim and tire have been removed from a vehicle hub, as shown in U.S. Pat. No. 4,203,382, have been used.
Another approach to the problem is shown in U.S. Pat. No. 4,277,107 were specially designed bolts are used to secure the tire on its rim to the wheel hub so as to make it difficult, if not impossible, to remove the wheels from the hubs.
Other approaches include the use of color-coded tires as well as molding identification marks into the tire.
The above described approaches have been only partially effective because they act simply as psychological deterrents and do not attack the basic incentive for the "quick change-out", i.e. the fact that a wheel rim carrying a good tire can be quickly swapped for another wheel rim carrying a less desirable tire.